Tubular bend and method of making same



Dec. 11, 1928. 1,694,430

B. c. ROOT TUBULAR BEND AND METHOD OF MAKING SAME fiSheets-Sheet 1 Filed Jan. 24 1927 Dec. 11

B. C. ROOT TUBULAR BEND AND METHOD OF MAKING SAME Filed Jan. 24, 1927 2 Sheets-Sheet 2 v fiwen ar: fierZa/eZZ a-fioi WW Patented Dec. 11, 1928.

V UNlTED BERTWELL o. 3901? DE B 1N, IEW AMFtiHISE. ASSLGNOn To Bnown ,qonran-Y,

9F BER I NEW HAMBSHIBE, A ncession or name. 1

T LAR BEN AF M EQPP? MAKE Application filed January 24, 1927. Serial No. 162,946.

This invention relates to tubular bends,-and has for its object the production or" such bends "from strai htv tubes, and more particularly from tubes formedirom fiber such as wood pulp. 1

Such tubes may be produced by winding a web of pulp from a Fourdrinier wire or other web-forming mechanism, on a mandrel until a wall of the desired thickness has been built up, whereupon th'etube is removed from the mandrel and thoroughly dried. The convolutions of a tube thus produced are sufiiciently interielted or matted together to constitute a substantially homogeneous or nonlaminated wall. hen used as a pipe for fluids or as a conduit for electric wiring systems, it is customary to'treat the tubes with a thermo-plastic waterproofing material, e. g. pitch, in a manner to permeate the same, thereby also strengthening and rigidilying the same, and increasing their dielectric properties.

In installing a pipe or conduit system, bends of variouscurvatures are sometimes necessary. This invention provides a simple and economical method of making sound, well-appearing bends from-straight fiber tubes.

In accordance with the method of the'present invention, aseries of wedge-shaped cutouts are formed in the wall of the straight tube prior to its treatment with waterproofing materal. The tube is then bent until the adjacentends of the sections formed by the out outs substantiallyabut, whereupon the sec? tions are fixed in this position. The bend is then treated with a thermoplastic waterproofing material to reflect its permeation with suich material. This treatment also produces an intimate bonding of the ends of the sections, so that the resulting bend is rigid, durable, and not liable to leakage.

The invention maybest be understood from the following more detailed description thereof, when considered in conjunction with the accompanying drawings, wherein Figure 1 represents in front yiew a straight fiber tube having cutouts formed therein and conditioned for bending.

Figure 2 is a similar yiew, showing the mannor in which the tube is bent.

sul imt bend.

Figure {l is a section on the line 4l-+4 of Figure 3. i

Figure 5 represents in front view a straight tube cond tioned for forming a compound bend; v

Figure 6 is a front view showing the manner in which the curvature.

Figure 7 is a left end View of the resultant bend. f I

Referring to Figure ,1 of the drawings, at 1 is indicated a straight fiber tube, as yet untreated with waterproofing material, from which the bend is to be formed.

series of spaced, wedge-shaped cutouts 2 are formed in the wall of the tube by sawing orotherwise cutting sections therefrom. Each cutout decreases in width tro n o'ne side of the tube toward its opposite side 1 butterminates sufficiently short of the other side to leave the tube continuous. Thetube as conditioned for bending thus COHSlStSOl a series oat sections 3 of trapezoidal 'torm', joined'together tube isbent to compound integrally at their wider bas'eportions 4: by

therebetwee-n, or both, thecurvature of the resulting bend may be ,varied. i

The tube is bent, as indicated in Figure 2, until the adjacent ends 2 of th'e'sections sub- 'stantially abut, whereupon the sections are TfllblllS end, fabric 5,

fixed in this position. I such as cotton duck, is then wrapped tightly around the bend-and maintains the sections against displaceme-i-it. A pair of reinforcing strips or pieces 6, of the appropriate curvature, are also prefterably then fastened to the bend at the bases otthc sections toaid in maintaining the sections against displace ment and also {to strengthen or, reinforce'the bend where t s most'liable to failure." The remtorcingstiu-ps may be and preferably are made of fibrous material and maybe formed .gether moist intertelted cellulos c mater a; in a mould of the proper form;

by pressing until ith-as permanently acquired the shape of the mould. The moulded pieces after being dried arertastened to the bend, preferably by wooden pegs Tsimilar to those sometimes used in pegging shoes. To facilitate pegging, staigti'rig aperturesof a depth less than the length-ct thepegs may be formed inthe material, a fiterfwhich the pegs may be "inserted forms the hole and drives the peg, is prefer ments of this invention, it is evident that into the apertures and driven into the unperforated material. Where available, however, the usual peggmgmachme,which both ably employed.

The bend is then treated with a thermoplasticwvater-proofing material, e. g, pitch, in a manner to eifect'a permeation of the fibrous material and the bonding together of the sections at their ends. This may beaccomplished by the use of a pitch of medium hardness, and sufficiently liquefiable by heat at a moderate temperature to yield a liquid of the proper viscosity to penetrate the bend without burning it. The impregnation or permeation of the bend may also, if desired, be accomplished in a closed vessel under pressure somewhat greater than atmospheric pressure. Preferably, a plurality of bends are immersed in a bath of the liquefied pitch for a sufficient time, under pressure, to permitthe pitch thoroughly to impregnate and permeate the wall of the bends and to fill the pores and interstices thereof and coat the fibres thereof. On removing the bends from the bath, the pitch hardens and firmly bonds together-the sections at their ends, and leakproofs them. V

a The method of the present invention also makes possible the production of a compound bend or one whose axis lies in -more than one plane. This maybe accomplished, as shown in Figure 5, by forming spaced cutouts 8, which terminate along spiral lines 9, or lines; of other predetermined configuration, rather than along straight lines. lVhen a tube thus conditioned for bending is bent so that the adjacent ends of the sections 10 abut as shown in Figure 6, a compound bend, i. e., a bend whose axis lies in more than one plane, is produced. Fabric 11 is then wrapped-tightly around the bend to maintain the sections against lateral displacement, and

a pair of fibrous reinforcing strips 12, moulded to the appropriate curvatures, are then pegged to the bend. at the bases of the sections, whereupon the bend may be treated with pitch or other thermoplastic waterproofing material, as hereinbefore described.

Employing the method hereinbefore described, bends of considerable sharpness may be readily and economically formed. The

bends thus made are not liable to leakage, and are rigid, sound and well-appearing.

Having thus described certain embodithey are subject tochange and modification,

Without, however, departing from the spirit 0r scope of invention as defined by the appended claims.

I claim 1. A method of making bends from straight,

V fiber tubes, whichjcomprises forming a series of spaced, wedge-shapedicutouts in the wall tions-of trapezoidal form; bending the tube A until the adjacent ends of the sections sub stantially abut; and bonding together the abutting ends of the sections.

2. A method of making bends from straight fiber tubes, which comprises forms I with a thermoplasticwaterproofing material in a manner to bond together the abutting ends of the sections.

3. A method of making bends from straight fiber tubes, which comprises forming aseries of spaced, wedge-shaped cutouts in the wall of the tube, thereby leaving a seriesof sections oftrapedoizal form; bending the tube untilthe adjacent ends of the sections substantially abut; wrapping-a fabric tightly around the bend to maintain the sections against displacement; and treating the bend with a thermoplastic waterproofing material. 4. A method of making bends from straightnoel tubes, which comprises forming a series of spaced, wedge-shaped cutouts in the wall of the. tube, thereby leaving a series of sections of trapezoidal form; bending the tube until the adjacent ends of the sections substantially abutjfastening reinforcing strips to the bend to maintain the ends of the sections in abutment; and treating the bend with thermoplastic waterproofingmaterial in a manner to bond together the abutting ends. v

5. A method, of making bends from straight'fiber tubes, which comprises forming a series of spaced, wedge-shaped cutouts in the wall of the tube, thereby leaving'a series of sections of trapezoidal form joined together at their wider base portions by the tube wall; bending the tube until the adjacent ends of the sections substantially abut;

wrapping afabric tightly around the bend to maintain the sections vagainst displacement; fastening a pair of reinforcing strips of. theappropriate curvature to the bend at the base portions of the sections to maintain the ends of the sections in abutment; and

treating the bend with thermoplastic waterproofing material, v

6. A method of making bends from straight fiber tubes, which comprises forming a series of spaced, wedge-shaped cutouts...

in the wall of the tube, thereby leaving a series of sections of trapezoidal form joined together at theirwider base portionsby the tube wall; bendingflthe tube until theadjacontends of the sections substantially abut, wrapping a fabric tightly around the bend to maintain the sections against displacement; pegging fiber reinforcing strips of the appropriate curvature to'the bend at the base portions of the sections; and treating the bend With thermoplastic Waterproofing material in a manner to permeate the fibrous material and to bond together the adjacent ends of the sections.

7. A fibrous tubular bend, comprising a plurality of integrally joined sections bonded together in abutting end-to-end relation.

8. A fibrous tubular bend, comprising a plurality of integrally joined sections fixed and bonded together in abutting end-to-end relation and permeated With Waterproofing material.

9. A fibrous tubular bend, consisting of a series of sections of trapezoidal form integrally joined together at their Wider base portions and permeated and bonded together at their adjacent ends With a thermoplastic Waterproofing material.

10. A fibrous tubular bend, consisting of aY series of inte ral sections of tra ezoidal form ,Wrapped tightly about with a fabric and permeated throughout and bonded together at their adjacent ends With a thermoplastic Waterproofing material.

11. A fibrous tubular bend, consisting of a series of integral sections of trapezoidal form Wrapped tightly about With a. fabric-and exteriorly reinforced With strips, said sections being permeated throughout and bonded together at their adjacent ends With a thermoplastic Waterproofing material.

12. A fibrous tubular bend, consisting of a series of integral sections of trapezoidal form tightly Wrapped about With a fabric and reinforced by fibrous strips exteriorly at their base portions, said sections being permeated and bonded together at their adjacent ends With thermoplastic Waterproofing material.

13. A fibrous tubular bend, comprising a plurality of integrally joined sections bonded together in abutting relation and per meated With a thermoplastic aterproofing material, the axis of said bend lying in more than one plane.

1A. A fibrous tubular bend, comprising a series of integrally-joined sections in abutting end-to-end relation and exteriorly reinforced, sald sections bemg permeated throughout and bonded together at their adjacent ends With Waterproofing material.

15. A fibrous tubular bend, comprising a series of integrally-joined sections of trapezoidal form n abutting end-to-end relation and reinforced eXteriorly at theirv base portions, said sections being permeated throughout and bonded together at their adjacent ends With Waterproofing material.

16. A fibrous tubular bend, consisting of a series of integral sections of trapezoidal form Wrapped tightly about With a fabric and exteriorly reinforced.

17. A fibrous tubular bend, consisting of a series of integral sections of trapezoidal form Wrapped tightly about With a fabric and exteriorly reinforced, said sections being permeated throughout and bonded together at their adjacent ends ith Waterproofing material. I

In testimony whereof I have affixed my signature.

BERTWELL C. ROOT. 

